Ganciclovir is an antiviral compound that has been used in the United States as well as several other countries for years. Liquid ganciclovir for oral administration has been known to be made from a powder of ganciclovir taken from a capsule and prepared to a concentration of 100 mg/ml of ganciclovir at a pH of 4.5. See, Am. J. Health Sys. Pharmacy, September 1999, vol 56, 1738-41. Additionally, an ophthalmic gel composition with ganciclovir has been described in which the concentration was about 0.15% and had a pH of about 7.4. Parenteral compositions of ganciclovir and its salts are described in U.S. Pat. No. 4,355,032. One parenteral composition that is currently being used is a lyophilized powder product of ganciclovir salt, namely ganciclovir sodium, sold in the United States under the trade name Cytovene®. This lyophilized powder product, supplied in a glass vial, requires reconstitution and dilution prior to administration to a patient.
There are at least three perceived drawbacks with the current lyophilized product: a) the lyophilization process is expensive, increasing the manufacturing cost per vial on an industrial scale; b) the reconstitution and dilution requires aseptic technique on the part of the health care giver, which could lead to occasional sterility compromise; and c) the product has a pH of about 11, which is not acceptable for some patients due to injection site reactions.